[Geopackage] Preparing for GeoPackage 1.0.2
bradh at frogmouth.net
Sat Dec 26 20:25:24 EST 2015
On Sat, 26 Dec 2015 11:21:04 AM Jeff Yutzler wrote:
> The SWG has recently voted to recommend to the OGC Technical Committee to
> adopt the working version of the GeoPackage specification as Version 1.0.2.
> For more details, please see my blog post:
There are two issues that you aren't considering in that text.
The first is that the change in #132 means that any implementation that has
extensions will be generating non-compliant gpkg files (since "The definition
column value in a gpkg_extensions row for those extensions SHALL contain the
sub-annex name and as a reference "). That isn't likely to cause problems (but
then, it probably could be "should") but it would be worth noting.
The other is that #137 is a breaking extension, which isn't what extensions
should be for (extend, not change). There is a warning (even in bold!) but
there is no way that the producer can possibly check that all consumers know
how to handle new-style CRS WKT. It might have been possible in a network
scenario, with some kind of protocol negotiation, but it doesn't work in a
mass-market offline tool.
I do have a suggestion, and that is that the extension should add a new column
to the gpkg_spatial_ref_sys table (srtext2, or whatever name the committee
would like to agree on), so that consumers that can handle the new-style WKT
if available, but would still be able to use the old WKT if they haven't been
I know you want to get 1.0.2 out, but I think a little more work on that
extension is warranted.
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